Nutrition Spotlight

There is no question that consuming enough calcium is essential for keeping bones healthy and strong, but a new study sheds doubt on the benefits of calcium supplements for post-menopausal women.

Researchers at the University of Auckland in New Zealand examined results from 11 randomized controlled trials involving nearly 12,000 patients. The trials, which lasted an average of four years, involved giving half the participants calcium supplements (which did not contain vitamin D) or a placebo. They found that among the women who took the calcium supplements, there was a 31 percent increase in the risk of heart attack.

Although the exact mechanism is still unclear, researchers believe that, unlike calcium ingested from food, supplements can boost blood levels of calcium, thereby increasing one’s risk of a heart attack.

While the researchers acknowledge the increase in risk is relatively small, the widespread use of calcium supplements significantly increases the number of women who could be adversely affected. Although additional studies are needed, some cardiologists are recommending that patients with osteoporosis should not be treated with calcium supplements. It is still important, however, to consume sufficient calcium from foods such as dairy products and green leafy vegetables.

In an editorial accompanying the study published in the British Medical Journal, cardiologist Dr. John Cleland wrote, “It is not clear whether [calcium supplements] really increase the risk of heart attacks or strokes.” However, he continued, “they do appear to be a waste of time and effort, and we should probably stop using them.”

The shelves of vitamin and health-food stores are packed with products containing glucosamine—a natural compound found in healthy cartilage—with labels promising relief from back and joint pain. Despite little evidence to support these claims, sales of glucosamine in 2008 totaled $872 million in the U.S. and $2 billion worldwide.

The results of a new study, however, could put a damper on those big sales. In what has been called the largest and longest trial of glucosamine, participants experienced no change in their levels of pain, disability and quality of life after taking the supplement for six months.

Researchers from Oslo University Hospital in Norway gave 125 patients with lower-back pain and osteoarthritis 1,500 milligrams of oral glucosamine. A second group took a placebo for the same time period. All participants were evaluated at the beginning of the study and again at six weeks, three months, six months and one year. Neither group reported any reduction in pain or improvement in quality of life.

For some us, just the thought of a favorite food can prompt us to start salivating and plotting our next meal. And according to a new study, just how strongly people respond to food cues—thoughts, smell and sight—may be affected by whether or not they are overweight.

Danielle Ferriday, a graduate student at the University of Bristol in the United Kingdom, and her faculty advisor Dr. Jeffrey Brunstrom devised a study to determine if overweight and lean people respond differently to food cues. They recruited 52 normal weight and 52 overweight women and exposed them to the sight and smell of pizza. In addition to monitoring their psychological responses, they tracked how much the women salivated when they smelled the pizza and again when it was placed in front of them.

The lean participants salivated about the same amount when smelling and then seeing the pizza. The overweight women, however, salivated about one-third more once the pizza was actually placed in front of them. And compared to the lean women, the overweight women also expressed a greater desire to eat the pizza. However, despite this increased desire, they didn’t eat anymore than the lean women, even though both groups were told to eat as much as they wanted to.

Ferriday and Brunstrom theorize that the overweight women’s heightened sensitivity to food cues may not make them want to eat more in a single sitting, but may spur them to eat more frequently and develop unhealthy eating habits that lead to weight gain. What is less clear is how this heightened sensitivity develops in some people and not others. For example, are people born with a greater desire for food or is this a learned behavior? Additional studies are needed to answer these questions.

Furthermore, although this study involved women, “we suspect that the findings would apply to men too,” says Ferriday.

I wholeheartedly agree with Maryellen. Here is an excellent article about the importance of calcium, including the flaws in the study that ACE shared with us in the e-newsletter. Do not rely on the mainstream news media to make your health decisions.
CALCIUM SUPPLEMENTS PLAY AN IMPORTANT ROLE IN MAINTAINING BONE HEALTH —Meta-analysis does not undermine entire body of research on essential mineral—
WASHINGTON, D.C., July 29, 2010 – A broad range of scientific research has demonstrated that an adequate intake of calcium plays an important role in building and maintaining optimum bone mass, and a recent meta-analysis published online in the British Medical Journal should not cause consumers to doubt the value of calcium supplements for maintaining bone health.
“Adequate calcium intake is vital to building and maintaining healthy bones, and to preventing osteoporosis—which is caused by a failure to build adequate bone mass or by bone loss that occurs as we age. Most people do not get enough calcium from diet alone, and this is where a calcium supplement can be important to consumers of all ages,” said Andrew Shao, Ph.D., senior vice president, scientific & regulatory affairs, Council for Responsible Nutrition. “The results from this meta-analysis does not undermine the value calcium supplements offer to those concerned with maintaining or increasing bone density, as years of research shows these products do.”
For example, the analysis could have potentially included over 300 scientific studies on calcium supplementation’s effect on bone, but only 15 randomized clinical trials were deemed “eligible for analysis.”
Further, seven of the 15 trials evaluated had no, or incomplete, data on cardiovascular outcomes, and only five of the 15 studies accounted for almost all of the cardiovascular outcomes. Further, because the researchers chose to exclude any trials administering calcium plus vitamin D, many large, important trials—including the Women’s Health Initiative, which found calcium plus vitamin D had no effect on the risk of coronary heart disease or stroke—were not included.
“The authors characterize these findings as though all of the selected studies suggest increased risk. In fact, the opposite is true: most of the studies do not suggest increased risk,” says Dr. Shao. “Bone health is one of the most common reasons why healthcare professionals recommend calcium supplements; there are other health benefits that may be associated with calcium supplementation, such as reduction of colon cancer risk. This is not even considered by the authors. It’s unfortunate that these researchers are making sweeping judgments about the value of calcium supplements by only assessing a handful of handpicked studies.”
Dr. Shao also pointed out that none of the original studies included in the meta-analysis were designed to evaluate cardiovascular outcomes. Additionally, the data on cardiovascular events was never previously published, so the meta-analysts had to track the information down separately, in some cases, 10 even 20 years after the original study was published.
“Meta-analysis can be a useful tool for scientific evaluation, but we have to recognize its limitations, and keep in mind that its findings are based on a collection of past studies that may have different designs, doses and study populations,” says Dr. Shao. “This analysis should not dissuade consumers, particularly young women, from taking calcium supplements. They should talk with their doctors about their current and long-term needs and determine how much calcium they are getting from their diets, and supplement accordingly—likely in combination with vitamin D.”
The Council for Responsible Nutrition (CRN), founded in 1973, is a Washington, D.C.-based trade association representing dietary supplement manufacturers and ingredient suppliers. In addition to complying with a host of federal and state regulations governing dietary supplements in the areas of manufacturing, marketing, quality control and safety, our 70+ manufacturer and supplier members also agree to adhere to additional voluntary guidelines as well as CRN’s Code of Ethics. Visit www.crnusa.org.

I agree with these comments...my residents at my retirement village were horrified when they read this anti-calcium article in the paper. It was the talk of the town for several days, as they were bombarding me with questions regarding the safety of taking Calcium. Yikes - take that calcium!

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